State regulators have approved a $32.5 million rate increase for Kansas City Power and Light to offset the utility's costs of providing service.

The Missouri Public Service Commission announced yesterday the rate increase would cost the average residential customer about $4 a month.

The decision also continues a fuel adjustment clause that allows Kansas City Power and Light to adjust customer bills up to twice a year to reflect any change in its fuel and purchased power costs. The utility also will continue a low-income residential customer assistance program.

State utility regulators have publicly released a confidential report detailing how much money has been earned by Ameren Missouri.

The Missouri Public Service Commission decided Tuesday to unseal a November report that has been at the heart of a complaint. The complaint alleges the St. Louis-based electric company was earning more than it was allowed to.

The newly released documents also include testimony from utility regulation consultants hired by Noranda Aluminum, which is leading the challenge of Ameren's electricity rates.

Gov. Jay Nixon has appointed his top legislative aide to serve on a Missouri commission that regulates utility companies.

Nixon said Friday that he had appointed Daniel Hall to the Missouri Public Service Commission.

Hall, of Columbia, has served as the governor's legislative director since Nixon took office in 2009. Before that, Hall was a senior counsel to Nixon in the attorney general's office. He also has held various other positions in state government and worked as an attorney in private practice.

Ameren Missouri customers can expect to see a slightly lower bill after state regulators determined the utility owes its electric customers slightly more than $26 million for failing to include some revenue in its calculations.

The Missouri Public Service Commission approved an order Wednesday for the St. Louis-based company to refund the money to customers. But Ameren Missouri won't be sending out checks. Instead, the $26.3 million will be applied by adjusting a fuel charge that customers otherwise would pay.